Microsoft will find itself in dock (again) today when the patent infringement case brought against it by little-known, privately-owned technology developer Eolas comes to the US District Court for Eastern Illinois.

At the heart of the case is a patent granted to the University of California but administered by Eolas, a firm set up in 1994 by the inventors of the technology described in the patent to capitalise upon it. Indeed the Regents of the University of California are named as joint plaintiffs in the case.

The patent in question is number 5,838,906, entitled 'Distributed hypermedia method for automatically invoking external application providing interaction and display of embedded objects within a hypermedia document'. Filed in October 1994, the patent was granted in November 1998. Essentially it describes how a user can use a web browser to access and execute a remotely stored program object that has been embedded in a web page.

Eolas contends that Microsoft's ActiveX technology does just that and more to the point does so without Eolas' permission. Its 1999 suit originally named Windows 95 and 98, and Internet Explorer as offending items, and demands they be banned from sale. These versions of Windows have long been superseded, but Eolas may yet add other versions of the operating system to its complaint.

The suit also seeks unspecified damages from Microsoft based on sales of those products within and without the US. Microsoft tried to have the judgement on the level of damages restricted to US sales only, but the case judge, James B Zagel, recently denied its motion.

Microsoft filed last November to have the case dismissed, but Judge Zagel ruled that it did have a case to answer, hence the trial which begins today at 10:30am Chicago time.

Eolas' patent also covers plug-in technology developed by Netscape to allow interactive content to be delivered through its Navigator browser, now owned by AOL. Sun's Java technology might also be considered to infringe 5,838,906 since it was developed, in part, as a mechanism to deliver applications via web pages. Sun began work on Java in 1991, though it was only made public in 1995. Mosaic, the browser on which IE is based, was released in 1993. ®